(1) Field of the Invention
This invention relates to agricultural irrigation and more particularly to center pivot irrigation systems. Farmers operating center pivot irrigation systems have ordinary skill in this art.
(2) Description of the Related Art
Center pivot irrigation systems are widely used in irrigating cultivated farm lands.
A center pivot system has a vertical pipe supplying water to a movable horizontal pipe. One end of the horizontal pipe is attached to the vertical pipe and supported by a plurality of vehicles. The plurality of vehicles move in a circle around the center pivot. Water is sprinkled from the horizontal pipe and the vehicles move continuously. This results in the wheels of the vehicles running continuously over wet cultivated soil.
As a result, ruts are formed from the continuous and repetitive movement of the wheels of the vehicles over the wet ground.
This problem has been recognized in the art. BEAN, U.S. Pat. No. 4,059,911 recognized this problem as early as 1975 and sought to correct it by having plows attached to the vehicles which would plow from the mounds of soil adjacent to the ruts into the ruts. Also Soviet Union Patent 1,551,287 in 1990 recognized the problem and sought to correct it by sheltering the vehicle from the sprinkling water along the vehicle.
Before this invention some people sought to change the track of the vehicles. One way of accomplishing this was to cut the horizontal pipe between the center pivot and the first vehicle. Then change the distance from the center pivot to the first vehicle by moving the entire horizontal pipe and all its supporting vehicles. Normally, the change was two or three feet so that the new track of the vehicle wheels would be separated from the rut previously formed. Then with the distance change the horizontal pipe was reconnected either by removing a section of pipe, or adding a splice or spool into the pipe.